Supercritical Ethane Processing of ZIF‐8 Membranes towards Pressure‐Resistant C3H6/C3H8 Separation

Abstract

ZIF‐8 membranes have shown great promise in industrial‐scale C3H6/C3H8 separation. Nonetheless, sustainable preparation of pressure‐resistant ZIF‐8 membranes remains a grand challenge. In this study, we pioneered the use of supercritical ethane (scC2H6) as reaction medium for preparing pressure‐resistant ZIF‐8 membranes. Membrane growth in neutral organic environment was proven to have less disturbance to structure integrity compared with supercritical CO2 (scCO2). Gas permeation results indicated that obtained ZIF‐8 membrane exhibited an ideal C3H6/C3H8 selectivity of 172.1 with C3H6 permeance of 5.9×10‐9 mol·m−2·s−1·Pa−1. Of particular note, the membrane maintained stable C3H6/C3H8 selectivity of ~150 with C3H6 flux of ~1.6×10‐3 mol·m−2·s−1 at operation pressure of 6 bar, which was significantly different from ZIF‐8 membranes obtained from scCO2 reaction medium. Through combining with advantages of zero pollutant discharge and full ligand recovery, our protocol holds great promise in sustainable preparation of pressure‐resistant ZIF‐8 membranes towards practical application in high‐purity C3H6 production.